Here would be the ideal healing strategy for this fight:
As was done last night, five healing this allows for more dps for the crunch. The ideal setup in my mind would be two druids, a HL paladin, a shaman, and a holy (or even disc) priest (though a second shaman or even a–god forbid–FoL pally could suit this last role as well in case of chronic priest shortage).
The tank healer, being the HL pally, would want to be in the front center range (ideally pointed toward the center meeting place for minimal time on the move should they get the pact on them), with the main tank beaconed. They can then heal the off tank as they take blood mirror damage, and other wise heal raid. Running as close to a 100% uptime of JoL here helps a lot. I personally have been keeping a sacred shield running on the top dps mage, just because they usually get bit early and you don’t want your bite dying (especially when they are so squishy in this kind of a fight) and it also provides a considerable dps boost (at least until the Inc. Absorbtion nerf lands). You should also be using your hand of salvation at the beginning of the fight to try and land a vampire bite on the ideal candidate. For divine pleas, just do it early and often and always pop a CD with it (though watch your avenging wrath near the air phase, you don’t want to get caught unable to bubble when it’s your turn for a dsac).
Paladins should also be running shadow resist aura (as should any other paladin specced into AM). If the OT is a prot pally and you only have one holy pally in raid, then the OT should bubblesac the first whirlbolt phase, with an aura mastery chained with it from the holy pally, and then the holy pally should bubblesac the second airphase, with another aura mastery chained to it from someone else in raid. (You want the OT to dsac the first one so that forbearance would have worn off should they need to divine protection later in the fight.) To note, bubble out of the fear, but then wait to pop dsac/AM until she actually starts whirlbolting, for maximum benefit.
For druids: rejuv, rejuv, rejuv. Druids should each stand on a side, around the center, for optimal raid coverage. With so much raid damage, this is very much a druid fight, and keeping continual hots rolling raid wide does amazing things here. Rejuv is going to be your bread and butter here, and should account for the vast majority of your healing, especially during the brutal raid damage in the beginning, and in particular having them up and rolling raidwide going into air phases is vital. Brezzes may be needed, and save your innervate for those brezzed or a suprise mana pinch, if you can.
The shaman and priest each stand to a side as well, just to help maintain optimal coverage. Here their job is purely utility, to help with tank heals, help with raid heals (in a triage manner preferably), and, especially for the priest, to take care of the people who receive flames and the pact. A priest CoH on the pact is amazing (and should ideally be saved for it), as is a chain heal once they get bunched in the center. In lieu of a holy priest, a disc priest (on raid heals) would also do well here, with shields, penance triage, and so forth. Having these people focusing on this should prevent a lot death issues.
(If you do have a–*shudder*–FoL pally in here, they should be helping with tank heals, and then triage healing debuff recipients with holy shocks, FoLs, and so forth. They should have aura mastery, though they will likely not have dsac–though it might well be worth respecing into it for this fight, the loss of 5% crit is worth it for the raid damage wall in my mind.)
The priest should also fear ward themselves around 10 seconds after the pull, and again after the first incite terror (done in this manner, the CDs should line up) to be available for triage healing (and even a pinch Divine Hymn) going into the air phase. The shaman will also have a grounding totem down. Additionally, from what I can tell, the ideal time to mana tide seems to be around 25-35% of the way into the fight. This is because as more people get bitten, less and less healing is required, so the most intensive healing will be at the start of the fight. After bites start going around, personal mana regen methods should be adequate.
Oh, and if there are shadow priests in raid, they should fear ward non-priest triage healers, followed by the other healers, not themselves. Make sure they use the above recommended timing.
Hopefully the other healers can chime in here with their own perspectives on this fight, and any corrections or clarifications should I be wrong on any point.
Bubblesacing Raids since 2009,
Naz